TOKYO — Kylie Masse had just set an Olympic record in the 100-meter backstroke heats on Sunday night in the Tokyo Aquatic Center.

"Having the record was amazing,'' the Canadian said. "I was happy to have achieved that, for one or two minutes.''

Regan Smith can relate. The rising U.S. swimming star from Lakeville broke Masse's record in the next heat.

Masse's time: 58.17 seconds.

Smith's time: 57.96.

Then, in the next heat, Australia's Kaylee McKeown finished in 57.88.

Unlike Masse and Smith, McKeown can spend the night as the Olympic record holder, and Smith goes into the final on Monday morning in Tokyo knowing that McKeown stands between her and Olympic gold.

Which was the case even before the heats. McKeown broke Smith's world record in the event in June, setting up a showdown that, if possible, became even more enticing on Sunday night.

Smith texted McKeown in May, when McKeown was chasing her records. The two can communicate in person on Monday if they so choose.

In an Olympics without fans or family members allowed, the U.S. swimmers gathered in the stands to cheer their teammates. They also cheered First Lady Jill Biden, who is making the rounds this week.